People are generally aware of the most common causes of hallucinations, like schizophrenia and a really high fever. But lesser known are the more rare causes; here are six you probably haven't heard about.

Michael Carl Nobles, Houston Man, Kills Himself In Hospital Room After Wive Gives Birth; Family Says He Had Been 'Distressed'

A man who took his own life by shooting himself in the maternity room of a Houston hospital, where his wife had just given birth an hour earlier, has been identified by Harris County medical examiners as Michael Carl Nobles.

An official cause for the man’s reported suicide is unknown. Houston police said arguing was heard from his wife Kendra Nobles’ maternity room at Willowbrook Methodist Hospital before shots were heard, the Daily Mail reported.

"Family members told our investigators that he had been recently distraught," Houston police spokesman John Cannon told the New York Daily News. The department’s homicide unit has not closed its investigation.

Thankfully, the newborn baby was not in the room at the time of the shooting, and Kendra Nobles was unharmed. Shortly after hospital officials discovered the 32-year-old man had turned a .380 pistol on himself, he was flown to nearby where he was pronounced dead.

"We are a level one trauma center, so depending on the acuity of a patient that will determine where a patient goes," Alex Rodriguez, spokeswoman for Memorial Hermann Hospital, told the New York Daily News.

Even with the hospital’s “no gun policy,” patients and family members are unsure if appropriate security measures were taken to ensure this tragedy never occurred.

“They should probably have more security, you know. If they’re going to let people in the institution like that,” hospital visitor Gustavo Manrique told KHOU.

“They probably need to have cops or something like that around if somebody has a gun or metal detectors or something.”

George Kovacik, public relations manager at Willowbrook Methodist Hospital, reaffirmed the hospital’s strict gun policy and called this an isolated incident.

"There are many signs visible throughout all of our facilities stating that the carrying of a handgun on the premises is prohibited by state law. We also have security officers and armed off-duty police officers working at all of our facilities around the clock," Kovacik said.